There exists today a variety of automated machines designed to provide products or services to a user while obviating the need for the owner, distributer, or other provider of those goods or services to be present at the transaction. Well known examples of such machines are food and beverage vending machines, newspaper vending machines, public telephones, video games and other amusement devices. One common characteristic of these machines is that they typically are operable only upon insertion into the machine of a predetermined, designated amount of money. Usually, these machines accept only certain coin currency such as nickels, dimes, and quarters.
Currency is deposited into a coin operated machine through one or more slots that are shaped only as large as needed to admit the intended coin currency. However, items having dimensions the same as or smaller than the intended coin currency can also be inadvertently or mischievously inserted into the slot. Therefore, to insure that the goods or services provided by the machine are only dispensed to those who have properly paid for them, coin operated machines are typically provided with a coin recognition and counting device.
Although coin recognition and counting are often accomplished using the same mechanism, they each have a different function. Coin recognition involves distinguishing valid coin currency from other objects, such as tokens, slugs, or foreign currency. For machines designed to accept more than one type of coin currency, coin recognition then further involves distinguishing between the various acceptable types of coin so that the user may be properly credited. Coin counting involves totalling the value of all the inserted coins that have been recognized as acceptable.
Coin recognition takes on many forms depending upon such factors as the value of the goods or services being provided by the machine. In its simplest form, coin recognition is accomplished by simply detecting whether an object has been inserted into the coin slot. See, for example, U.S. Pat. No. 5,125,492, issued Jun. 30, 1992 to D. H. Treleaven et al., which discloses an optointerrupter that detects an object entering the machine through a token chute.
More typically, however, coin recognition involves mechanically verifying that the dimensions and weight of the inserted object match the known dimensions and weight of the coin or coins for which the machine is designed. Moreover, United States coin currency is non-ferromagnetic and will therefore not be noticeably influenced by an impinging magnetic field. Accordingly, more sophisticated coin recognition devices utilize magnets to eliminate objects having the same dimensions and/or weight as the valid coin currency, but that contain substantial proportions of iron or other ferromagnetic materials. Elimination of ferromagnetic objects in these devices involves using the magnet to attract and separate the ferromagnetic objects, often by pulling them off one coin path and onto another which disposes of the object via a coin return or otherwise. Differentiating between valid coins has been accomplished by mechanisms that separate the coins based on their size and weight, after which they can then be counted.
It is also known to use an electromagnetic detector that is sensitive to metal coins to recognize and distinguish various types of coins. U.S. Pat. No. 4,234,071, issued Nov. 18, 1980 to S. Le-Hong, utilizes a tank circuit that is fed by an a.c. generator and a circuit that measures voltage variations in the tank circuit that result from metal objects such as coins passing by the tank circuit. This voltage variation is dependent on the characteristics of the coin passing by the detector and therefore provides a characteristic curve which can then be compared to stored curves to determine the type of coin.
Coin counting has also been accomplished in various ways. For example, the newspaper vending machines used to sell USA Today.TM. count coins by stacking them. Once the proper number of coins have been inserted, a bearing surface prevents upward movement of the coins by contacting the top-most portion of the edge of the uppermost coin and the bottom-most portion of the edge of the lowest coin is used as a cam surface that causes the door latch to release when the door is pulled by the user toward its open position.
More recently, coin operated vending machines have incorporated an electronic circuit that is used to count the recognized coins and to thereafter cause the good or service to be provided to the user. U.S. Pat. No. 4,216,461, issued Aug. 5, 1980 to R. L. Werth et al., discloses a vending machine having such a coin counter. Electronic circuits have also been used to monitor and store auditing information that includes the total amount collected by the vending machine. See, for example, U.S. Pat. No. 4,845,484, issued Jul. 4, 1989 to T. R. Ellsberg.
One disadvantage of some prior art coin recognition and counting devices is that the arrangements used to properly distinguish coin currency by, for example, size, weight, and magnetic characteristics, result in a complicated and somewhat bulky mechanism. It would therefore be advantageous to provide a coin recognition and counting device that minimizes the amount of mechanical manipulation required to distinguish valid coin currency from other objects.